Allen Formation

Allen Formation Stratigraphic range: Upper Cretaceous
Type	Geological formation
Unit of	Malargüe Group
Overlies	Anacleto Formation

The Allen Formation is a geological formation in Argentina whose strata date back to the Late Cretaceous (middle Campanian to early Maastrichtian.^[1] Dinosaur remains are among the fossils that have been recovered from the formation.^[2]

Vertebrate paleofauna

Dinosaurs

Dinosaur eggs are known from the formation.^[3]

Dinosaurs reported from the Allen Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Aeolosaurus[3]	Indeterminate[3]
Austroraptor	A. cabazai					Saltasaurus Saltasaurus egg
Lamarqueavis[4]	L. australis[4]			"Right coracoid with damaged sternal and omal extremities, and lacking acrocoracoidal process."[4]
Lapampasaurus[5]	L. cholinoi[5]			Elements of the axial and appendicular skeleton of a subadult individual.[5]
Laplatasaurus[3]	L. araukanicus[3]
Limenavis[3]	L. patagonica[3]			"Partial forelimb."[6]
Panamericansaurus[3]	P. schroederi[3]			"Five tail vertebrata, sacral vertebrae, left humerus and rib fragments."[7]
Pellegrinisaurus[3]	P. powelli[3]			"Dorsal and caudal vertebrae, partial femur."[7]
Quilmesaurus[3]	Q. curriei[3]			Femur and distal tibia.[8]
Rocasaurus[3]	R. muniozi[3]			"Partial postcranial skeleton."[9]
Saltasaurus[3]	S. loricatus[3]
Willinakaqe[10]	W. salitralensis[10]

Pterosaurs

Fragmentary fossils are known from the formation.^[3]

Pterosaurs reported from the Allen Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Aerotitan[11]	A. sudamericanus[11]	Bajo de Arriagada	Uppermost Allen Form.	Partial rostrum	The first unambiguous azhdarchid from South-America.

Mammals

The mammal fauna of the Allen Formation is known from seven teeth, which document the presence of several species.^[12]

Mammals reported from the Allen Formation
Genus	Species	Location	Stratigraphic position	Material	Notes	Images
Mesungulatum	M. lamarquensis	Cerro Tortuga		Two upper molars and a fragmentary lower molar	A dryolestoid
Groebertherium	G. stipanicici	Cerro Tortuga		One upper molar	A dryolestoid
Cf. Brandonia	sp.	Cerro Tortuga		One lower molar	A dryolestoid
Barberenia	B. allenensis	Cerro Tortuga		One upper molariform	A dryolestoid
Trapalcotherium	T. matuastensis	Cerro Tortuga		One first lower molar	A gondwanathere

See also

• List of dinosaur-bearing rock formations

Footnotes

1. Salgado, L., Coria, R. A., Magalheas Ribeiro, C. M., Garrido, A., Rogers, R., Simon, M. E., Arcucci, A. B., Rogers, K. C., Carabajal, A. P., Apesteguia, S., Fernandez, M., Garcia, R. A., and Talevi, M. (2007). Upper Cretaceous dinosaur nesting sites of Rio Negro (Salitral Ojo de Agua and Salinas de Trapalco-Salitral de Santa Rosa), northern Patagonia, Argentina. Cretaceous Research, 28(3):392–404.
2. Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, South America)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 600-604. ISBN 0-520-24209-2.
3. "63.10 Provincia de Rio Negro, Argentina; 5. Allen Formation," in Weishampel, et al. (2004). Page 604.
4. Federico L. Agnolin (2010). "An avian coracoid from the Upper Cretaceous of Patagonia, Argentina". Stvdia Geologica Salmanticensia. 46 (2): 99–119.
5. Rodolfo A. Coria; Bernardo González Riga; Silvio Casadío (2012). "Un nuevo hadrosáurido (Dinosauria, Ornithopoda) de la Formación Allen, provincia de La Pampa, Argentina". Ameghiniana. in press.
6. "Table 11.1," in Weishampel, et al. (2004). Page 215.
7. "Table 13.1," in Weishampel, et al. (2004). Page 269.
8. "Table 4.1," in Weishampel, et al. (2004). Page 77.
9. "Table 13.1," in Weishampel, et al. (2004). Page 270.
10. Rubén D. Juárez Valieri; José A. Haro; Lucas E. Fiorelli; Jorge O. Calvo (2010). "A new hadrosauroid (Dinosauria: Ornithopoda) from the Allen Formation (Late Cretaceous) of Patagonia, Argentina" (PDF). Revista del Museo Argentino de Ciencias Naturales n.s. 11 (2): 217–231.
11. Novas, F. E.; Kundrat, M.; Agnolín, F. L.; Ezcurra, M. N. D.; Ahlberg, P. E.; Isasi, M. P.; Arriagada, A.; Chafrat, P. (2012). "A new large pterosaur from the Late Cretaceous of Patagonia". Journal of Vertebrate Paleontology. 32 (6): 1447. doi:10.1080/02724634.2012.703979.
12. Rougier, G.W., Chornogubsky, L., Casadio, S., Paéz Arango, N. and Giallombardo, A. 2009. Mammals from the Allen Formation, Late Cretaceous, Argentina (subscription required). Cretaceous Research 30:223–238.

References

• Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. 861 pp. ISBN 0-520-24209-2.